Cross-roll delivery table



Feb. 26, 1935. A. P. DIESCHER v CROSS ROLL DELIVERY TABLE 3 Sheets-Sheet1 Filed March 3, 1955 M. Mme/$0 M Feb. 26, 1935. A. P. DIESCHER CROSSROLL DELIVERY TABLE Filed March 3, 1933 3 Sheets-Sheet 2 I/YVENTOI? $1MATTORNEYS BY 624W,

Feb. 26, 1931 p sc 1,992,360

CROSS ROLL DELIVERY TABLE Filed March 5, 1935 5 Sheets-Sheet s //V l/E NTOR FIG 14 @527; Waryw ATTOFPNE Y8 Patented Feb. 26, 1935 UNl'lE DSTATES 1,992,300 (moss-non. DELIVERY TABLE August P. Diescher,Pittsburgh, Pa., assignor to Diescher Tube Mills, Inc., Pittsburgh, Pa.,a f corporation of Delaware Application March a, 1933, Serial No.659,530

19 Claims. "(01. 80-11) My invention relates to tube-making apparatus,and particularly to delivery tables for receiving rapidly rotating andlongitudinally moving tubes from cross-rolls.

In the operation of mills comprisingcrossrolls for reducing the wallthickness of tubular blanks, the walls of the finished tubes may berelatively thin, especially when the tubes are of large diameter. Inreducing the wall thickness of and elongating tubular blanks by means ofcross-rolls it is customary to employ a mandrel having adiameter whichis of such size as to loosely flt therein.

'Mandrels of required size and of suflicient strength to resist thepressure of the cross-rolls in reducing the wall thickness of tubularblanks being worked thereby are relatively heavy, as will beappreciated. When the delivered tube formed orptherwise damaged by theweight of the mandrel. as a result of the impacts received by the wallswhen the tube and the mandrel are delivered to the receiving devices.

Furthermore, when the rapidly rotating tubes are received by a deliverytable having rollers or other devices for engaging the tubesthat are notrotatable therewith, or if there is considerable relative movementbetween the tubes and the engaging surfaces, the outer surfaces of thetubes may be marred or scratched by the relatively stationary surfaces,and such damage may be suflicient to cause their rejection. Tubes areliable to be so damaged irrespective of the weight of the mandrel and'whether they contain a mandrel or not, although the liability of theirbeing so damaged is of course greater when they contain a heavy mandrel.

In accordance with the present invention, I provide a delivery table'inwhich the members for receiving and directly supporting the tubes andmandrels delivered from the cross-rolls are rollers which are mounted torotate with the rapidly rotating tubes without relative movement betweenthe engaging surfaces of the tubes and rollers. Most desirably andaccording to'an important feature of the present invention, these tablerollers are rotatable upon axes parallel to the longitudinal path of thetubes and are bodily movable along this path. The speed of this axialmovement may be as desired, but preferably it does not vary from that ofthe longitudinal move-4 mentpf the tubes to such extent that damage tothe outer surfaces of the tubes may occur. It is obvious that the mostdesirable speed from the standpoint of relative movement would be thatequal to the speed of longitudinal movement of the tube, although forpractical purposes the speed may vary somewhat therefrom without 5danger of damage to the tube.

Certain of these receiving rollers are substantially directly beneaththe tube and the mandrel contained therein in order that the tube may bedirectly supported at its lowermost portion upon which the mandrelrests. Accordingly, there will be no deformation of the walls of thetube by the weight of the mandrel such as might be caused if the tubewere supported entirely at other points.

Certain of the rotatable and movable receiving rollers are arranged toengage the tube on opposite sides thereof in order to act as guiderollers while the tube is rotating and is supported at least in part bythe rollers directly therebeneath.

The effect of the provision of rollers arranged in the manner describedabove is to insure that relative movements between the enga in surfacesof the tubes and the supporting means 5 therefor of the delivery tableare so limited that scratches or other marks on the surface of thefinished tube are avoided or are so slight as not to be objectionable.'-Also, deformation or other' damage of the relatively thin hot walls ofthe 3() tube is avoidedbecause the tube is supported substantiallydirectly beneath the portionsupon which the mandrel is supported.Furthermore, the rollers of the delivery table are provided withslightly convex surfaces and rounded edges. have thereby eliminated theusual sharp edges of such rollers which are a possible source of damageto the tubes.

The details of my invention will be described in connection with theaccompanying drawings, 0 in which Fig. 1 is a plan view of a cross-rollmill and a portion of a delivery table therefor constructed inaccordance with my invention; Fig. 2 is a view partially in elevationand partially in section on line IIII of the apparatus of Fig. 1 and atube being worked by the cross-rolls; Fig. 3 is a vertical section takenon line III-III of Fig. 6; Fig. 4 is an enlarged fragmentary view inelevation of a filler block for'the delivery table and parts associatedtherewith; Fig. 5 is a front elevation of a mandrel raising device shownin Figs. .1 and 2; Fig. 6 is a plan view of the delivery table andcertain associated apparatus; Fig. '7 is a side elevational view of theapparatus of Fig. 6, showing some parts of the apparatus not shown 5b ofFig. 6; Fig. 9 is a vertical section on line IX-IX- of Fig. 6; Fig. 10is an enlarged plan view of a link carrying two spaced rollers; Fig. 11.is a similar view of a link carrying a single roller; Fig. 12 is avertical sectional view of a portion of the delivery tablecomprising apair of rollers in engagement with a tube; Fig. 13 is a view similar toFig. 12 illustrating a single roller in position for supporting a tubeandmandrel; and Fig. 14 is an enlarged vertical sectional view of acylinder and associated parts of the mandrel-stripping mechanism.

Referring particularly to Figs. 1 and 2, the cross-rolling mill'l showncomprises a pair of oppositely disposed cross-rolls 2 and 3 having theiraxes inclined to each other and to the line of feed of a blank betweenthem. Disposed between the cross-rolls and on opposite sides of the passbetween them is a pair of adjustably mounted grooved guide rolls ordiscs 4 and 5 arranged on horizontal axes'and adapted to be driven inany suitable manner by means of drive shafts 6 and '7.

Whilethe apparatus of the present invention is adapted to be employedwith mills embodying cross-rolls of substantially any type, thestructure of the mill may correspond, for example, to that of the wallreducing and elongating mill shown and described in S'. E. DiescherPatent No. 1,870,- 209, granted August 2, 1932.

A tubular blank 9 and a mandrel 10 therein, and a portion of each ofwhich is shown in Fig. 2 in,an intermediate position in the pass betweenthe cross-rolls 2 and 3, are adapted to be received by a delivery table11, only a portion of which is shown in Figs. 1 and 2. The completedelivery table 11 is shown in Figs. Band '7, and enlarged detailsthereof are illustrated in Figs. 3 and 4 and 9 to 13, inclusive.

The delivery table 11 comprises an endless chain 12 that is mounted upona stationary frame work 13 and is adapted to be actuated by twospaced'sprockets 14 at the forward or right-hand end of the table asviewed in Fig. '7. At the opposite end of the table the chain 12 passesover idler sprockets 15.

The stationary framework 13 is divided into two sections 16 and 1'7. Thesection 16 is stationary except that its height may be adjusted' Thesection 17 is longitudinally movable in order to adjust the length ofthe framework to adjust the amount of slack in the chain. As best shownin Fig. 7 and in enlarged detail in Fig. 4, the sections 16 and 17 arenormally connected at adjacent ends on each side by means of what may betermed a "flller block 18.

A number of filler blocks or spacing blocks of various lengths may bemade available in order that the length of the supporting framework 13may be adjusted as desired. When the filler blocks 18 have been removedthe movable section 17 may be shifted to shorten or lengthen the tableas desired by means of a screw-threaded shaft 19 having a handwheel 20thereon and which operates to move a supporting casting 21 along aguideway in a base 22. Other filler blocks of appropriate length maythen be inserted. Both the stationary and the movable sections of theframe 13 may be adjusted as to height by means of jacks 23 which aredetachably 'connected by couplings 24 in order that they may be operatedeither individually or simultaneously by any suitable manual orpower-operated means.

The chain 12 comprises a series of pairs of spaced links 25 and spacedlinks 26 which alternate with each other throughout the length of thechain. Each third pair of links 25, one of which pairs is shown inenlarged detail in Figs. 1,0 and 12, is provided with an upright bracket2'7 upon which are mounted two rollers 28 having their .axes parallel tothe axis of a tube supported there- The links 25 and 26 are provided attheir sides with pairs of rollers 29 that are adapted to roll upon atrack 30 upon the tops of both sections of the frame 13.

Each third pair of links 26, which alternate with the pairs of links 25,is provided with an upright bracket 32 upon which is mounted a singleroller 33 having its axis parallel to the axis of a tube supportedthereon and which is adapted to engage tubes thereon substantiallydirectly therebeneath. The roller 33 is mounted upon an arm 34, one endof which has a pivotal support at 35 and the other end of which isvertically adjustable by means of a stud bolt 36 threaded into thebracket 32 and a nut 3'7 thereon. This vertical adjustment of therollers 33 relative to the rollers 28 is provided in 'order to insurethe proper contact of all of the rollers with tubes of diiferentdiameters.

The lower portion of the chain when passing beneath the movable section1'7 is supported upon' guideways 39 of angle shape that are illustratedin Figs. 3 and '7. A curved guideway 40 is provided at each end of thetable and in extension of the track 30. These guideways 40, which areillustrated in Figs. 2 and '7, insure that the several vlinks'25 and 26are transferred between the lower horizontal portion of the chain andthe upper horizontal portion gradually and without shock or jar such asmight be caused if the links changed their paths of movement abruptly.

As shown in Figs. 2, 3, '7, 8 and 9, two beams42 extend above thedelivery table 11 and have suspended therefrom a series of covers 43 forlimiting lateral movements of tubes while carried upon the rollers'28and 33. Each of the covers 43 comprises a pair of oppositely disposedinclined blocks 44 that are .laterally adjustable by means of a screw 45having right-hand and left-hand threads, and which may be engaged by acrank or wrench at its outer end to suitably space the blocks 44 .toadapt them for tubes of various diameters. v

The cross-rolls 2 and 3 may be driven by means of a motor 46, a' gearstand 47, and spindles 48 and 49 that are respectively connected to thecross-rolls 2 and 3. The guide discs 4 and 5 are driven through theirrespective shafts 6 and '7 by means of suitable power devices such aselectric motors, not shown.

The endless chain 12 is driven by means of a motor 51 and a gearmechanism 52 that is connected by universal joints 53 to a shaft 54having thereon a one-way clutch 55 which drives the sprockets 14. Theprovision of the one-way clutch permits the chain 12 to be drivenby thelongitudinal movement of tubes thereon in case the rate of movement ofthe tubes exceeds that at which the chain is being driven by the motor51.

The motor 51 and gear mechanism 52 are adjustable to confrom with theposition of shaft 54 and sprockets 14 by means of a screw 56 and a handwheel 5'7. The universal joints 53 permit relative horizontal orvertical adjustments of the sprockets 14 and shaft 54 and the gearmechanism 52.

Mandrel-stripping mechanism, which is located at the end of the deliverytable adjacent the mill 1 and is clearly shown in Fig. 8, comprises twofluid pressure cylinders 58, the details of one of which are illustratedin Fig. 14. A piston 59 in each of the cylinders is provided with aplunger 60 having a block 61, Fig. 8, at the outer end thereof that isadapted either to engage the side of a tube or to act as an abutmentagainst the end of the tube while the mandrel is being removedtherefrom. The details of the mandrel-stripping mechanism constitute nopart of the present invention but are described and claimed in mycopending application, Serial No. 672,250, filed May 22, 1933.

A mandrel-lifting mechanism is illustrated in Figs. 1, 2 and 5, and itcomprises a fluid pressure cylinder 63 that is connected by means of aplunger 64 to a member 65 for supporting a roller 66. The member 65 isguided in its vertical movements by two bolts 67 extending throughopenings in the member 65 and provided with nuts 68 that are adjustableto limit the upward movement of the member 65 and its roller 66.

It may be assumed that a tubular blank such asthe blank 9 shown in Fig.2 is passing through the cross-rolls 2 and 3 and contains a mandrel 10therein. The cross-rolls operate to rotate the tube and the mandrelrelatively rapidly and also to advance them longitudinally, although notnecessarily atthe same rate of longitudinal movement.

As the tube 9 and mandrel 10 advance to the right, as viewed in Figs. 2,6 and 7, the forward end of the tube first engages rollers 28 or aroller 33 of the delivery table 11 dependent upon the relative positionsof the tube and the chain. The tube is successively engaged by otherrollers 28 and 33 following those initially engaged as the correspondinglinks of the chain 12 move upward over the sprockets 15 and guideways 40to theupper leveland beneath the tube.

The rollers 28 and 33 are adapted to rotate with the tube, whereby thereis little or no relative rotative movement between these-parts. .Also,the longitudinal movement of the chain is such that any relativelongitudinal movement between the rollers and the tube is not sufilcientto cause any objectionable damage such as scratches or marks upon theouter surfaces of the tube. In case the tube emerges from thecross-rolls at a speed greater than that of the longitudnal movement ofthe chain, the latter may be actuated faster than its drivingconnections by reason of the provision of the one-way clutch 55 whichpermits the chain to move faster than it is driven by the motor 51. e

While the tube and mandrel are upon the rollers 28 and 33, the spacedrollers 28 guide the tube in its longitudinal movement in properposition upon the central supporting rollers 33, and also partiallysupport the tube and mandrel. The tube and mandrel are principallysupported, however, by the rollers 33, which are substantially directlybeneath the. portion of the tube for supporting the mandrel.

When the mandrel is smaller in diameter than the completed tube, theweight of the mandrel is supported by a relatively narrow portion of thetube, the wall of which may be relatively thin and hot. The singlerollers 33, which are substantially directly beneath this narrowportion, may be provided in such number and such extent of hearingsurface that there is no tendency to deform the walls of the tube byreason of the weight of the mandrel supported thereby.

The movement of the chain 12 and the rotation of the cross-rollscontinue until the tubular blank has passed completely through the milland the completed tube is supported entirely by the rollers 28 and 33.When the tube and mandrel are no longer rotated by the cross-rolls,their rotation soon ceases because of the retarding eflectof the rollers28 and 33 upon which they are supported. The movement of the chain 12 isthen stopped for the purpose of removing the mandrel from the tube. 1

The mandrel 10, which is preferably in the form of a hollow cylinder,may be withdrawn while the tube is clamped between the jaws 61 ofthemandrel-stripping mechanism. The latter may also serve as abutments forthe end of the tube adjacent the mill 1, when, for example, theapparatus is of the type in which the mandrel is secured to a movablemandrel head at the entrance side of the mill 1 which is withdrawntopass of the iness for a succeeding operation.

When the mandrel has been'withdrawn from the tube, the latter may betransferred laterally from the chain12 or the chain may beagain operatedto convey the tube to any suitable position along the path of the chainfor transfer to skids or other suitable device for conveying thefinished tube to a suitable location for other processing or for coolingand storage.

From the foregoing it will be noted that I have provided an arrangementby means of which a rotating and longitudinally moving tube even thoughit has relatively thin hot walls and contains a relatively heavy mandrelmay be received without danger of deforming or otherwise damaging thewalls of the tube, either by reason of relative movement between thetube and its supporting means, or of the weight of the mandrel containedtherein. This result is secured by providing a supporting means for thetube that rotates with the latter, while at the same time movinglongitudinally at a speed that sufficientlyv The tubes emerge from thecross-rolls with a 4 helical movement, the angle of which depends uponthe ratio of longitudinal movement to the rotative movement. liverytable rotate about axes parallel to those of the tubes, their movementlongitudinally or ax-' While the rollers of the debetween the engagingsurfaces of the rollers and p the tube. Accordingly, the outer surfaceof the tube is not marred by scoring or scratching as might be the caseif such relative movements were not eliminated.

The delivery table is of relatively simple construction and occupieslittle or no more space than that required for delivery tables of theprior art which do not provide the advantages that are present in theimproved table that I have provided.

While I have shown and described a specific ar-' rangement of thesupporting and guide rollers on their respective supporting links of thechain, other suitable arrangements for securing similar results withrespect to elimination of relative movements between tubes and thereceiving means therefor may be employed within the scope of myinvention.

It will be appreciated that the apparatus of the present invention issuitable for use in connection with either hot or cold tubes.

The foregoing and other advantages will be appreciated by those skilledin the art of constructing and operating apparatus for producing andhandling seamless tubes and mandrels therefor.

I claim: V

1. A table for receiving tubes from cross-rolls that rotate said tubeswhile advancing them longitudinally, said table comprising a series ofrollers adapted to support and to rotate with said tubes, about axesparallel to the tube axis, and power driven means independent of saidtubes for moving said rollers along the longitudinal path of said tubes,whereby a rotating and longitudinally moving tube may be received bysaid table substantially without relative movement between the engagingsurfaces of the tube and table.

2. A. table for receiving tubes of relatively large diameter and havingrelatively thin walls from cross-rolls that rotate said tubes atrelatively high speed while advancing them relatively slowlylongitudinally, said table comprising a series of rollers adapted tosupport and to rotate with said tubes about axes parallel to the tubeaxis, and power-driven means independent of said tubes for moving saidrollers along the longitudinal path of said tubes, said moving meanscomprising an endless member upon which said rollers are supported.

3. A table for receiving tubes from cross-rolls that rotate said tubesat relatively high speed while advancing them relatively slowlylongitudinally, said table comprising a series of rollers adapted tosupport and to rotate with said tubes about axes parallel to the tubeaxis, and means along the longitudinal path of said tubes, said movingmeans comprising an endless chain for carrying said rollers at a speedapproximately that of the longitudinal movement of said tubes, and powermeans for driving said chain.

4. Apparatus for receiving from cross-rolls tubes containing arelatively heavy mandrel of smaller diameter than the surrounding tube,said apparatus comprisinga series of rollers spaced along the path ofsaid tube as it is delivered from said cross-rolls for supporting saidtube thereon for rotation about its axis, certain of said rollers beingarranged to engage the bottom portion of said tube upon which themandrel therein is supported and other of said rollers being arranged toengage said tube to guide the latter in its movements.

5. Apparatus for receiving from cross-rolls tubes containing arelatively heavy mandrel of smaller diameter than the surrounding tube,

said apparatus comprising a series of rollers spaced along the path ofsaid tube as it is delivered from said cross-rolls for supporting saidtube therein for rotation about its axis, certain of said rollers beingarranged singly to engage the bottom portion of the tube upon which themandrel therein is supported and other of said rollers being arranged inpairs to engage opposite sides of said tube to guide the latter in itsmovements.

6. Apparatus for receiving from cross-rolls tubes containing arelatively heavy mandrel oi smaller diameter than the surrounding tube,said apparatus comprising a series oi. rollers spaced along the path ofsaid tube as it is delivered from said cross-rolls and for supportingsaid tube thereon for rotation about its axis, certain of said rollersbeing arranged in groups consisting of pairs of spaced rollers forserving as guides for said tubes and alternating with single rollers forsupporting the lowermost portion of said tube upon which is supportedthe mandrel contained insaid tube.

7. Apparatus for receiving from cross roll s tubes containing arelatively heavy mandrel of smaller diameter than the surrounding tubesaid apparatus comprising a series of rollers having axes parallel tothe tube axis and spaced along the path of said tube as it is deliveredfrom said cross-rolls for supporting said tube thereon for rotationabout its axis, certain of said rollers being arranged to engage thebottom portion of said tube upon which the mandrel therein is supportedand other of said rollers being arranged to engage said tube to guidethe latter in its movements, and means comprising an endless chain formoving said rollers along the path of said tube.

8. Apparatus for receiving from cross-rolls tubes containing arelatively heavy mandrel of smaller diameter than the surrounding tube,said apparatus comprising a series of rollers having axes parallel tothe tube axis spaced along the path of said tube as it is delivered fromsaid cross-rolls for supporting said tube thereon for rotation about itsaxis, certain of said rollers being arranged to engage the bottomportion of said tube upon which the mandrel therein is supported andother of said rollers being arranged to engage said tube to guide thelatter in its movement, and an endless chain to which said rollers aresecured and which is adapted to move said rollers along the path of saidtube at a speed approximately that of said tube.

9. A table for receiving tubes of relatively large diameter and havingrelatively thin walls from cross-rolls that rotate said tubes atrelatively high speed while advancing them relatively slowlylongitudinally, said table comprising a longitudinal series of membersfor rotating with a tube supported thereon, and power-driven meansindependent of said tube for actuating said members along thelongitudinal path of said tube at substantially the speed thereof,whereby there is substantially no relative movemerit between theengaging surfaces of a tube and said members.

10. Apparatus for receiving from cross-rolls tubes containing arelatively heavy mandrel, said apparatus comprising means beneath thetube and its contained mandrel and in approximate vertical alignmentwith the axes thereof for supporting them and for-rotating with saidtube, and means for actuating the supporting means longitudinally withsaid tube.

11. Apparatus for receiving from cross-rolls tubes containing arelatively heavy mandrel of smaller diameter than the surrounding tube,said apparatus comprising means in approximate vertical alignment withthe axes of a tube and its contained mandrel for supporting them and forrotating with said tube, and means for moving the rotatable supportingmeans along the longitudinal path of said tube while the latter issupported thereon.

12. The combination with a pair of cross-rolls from which tubes emergewith a helical movement, of a delivery table for receiving said tubesand comprising rollers for engaging said tubes and rotatable therewith,the axes of the rollers being parallel with the tube axis, and meansindependent of the movement of said cross-rolls and said tubes formoving said rollers longitudinally while they are rotating, whereby theresultant movements of the points of the surfaces of said rollers arehelical.

13. The combination with a pair of cross-rolls from which tubes emergewith a helical movement, of a delivery table for receiving said tubesand comprising rollers for engaging said tubes and rotatable therewith,the axes of the rollers being parallel with the tube axis, andpowerdriven means for moving said rollers longitudinally while they arerotating and at approxitnately the same speed as that of thelongitudinal movement of the tubes, whereby the angle of the resultinghelical movement of the points of the surfaces of said rollers isapproximately that of the movement of the tubes.

14. A table for receiving tubes from cross-rolls that rotate the tubeswhile advancing them longitudinally, said table comprising a series ofrollers adapted to support and to rotate with the tubes, an endlesschain on which said rollers are mounted, and driving means for movingsaid chain to carry said rollers along the path of the tube at a speedapproximately that of the longitudinal movement of the tube, saiddriving means including a one-way clutch whereby the chain and rollersare free to be moved by a tube moving faster than the chain is moved bythe driving means.

15. Cross-rolling apparatus comprising a pair of cross-rolls, a deliverytable for receiving tubes having mandrels therein from said cross-rolls,said mandrels being retractable through said cross-rolls for asubsequent operation, and mandrel supporting means between saidcross-rolls and said delivery table for engaging a mandrel during itsreturn movement and thereby relieving the tube from supporting saidmandrel while the latter is retracted.

16. Cross-rolling apparatus comprising a pair of cross-rolls, a deliverytable for receiving tubes having mandrels therein from said cross-rolls,said mandrels being retractable through said cross-rolls for asubsequent operation, and mandrel supporting means between saidcross-rolls and said delivery table for engaging a mandrel during itsreturn movement and thereby relieving the tube from supporting saidmandrel while the latter is retracted, said supporting means beingvertically adjustable whereby it may be moved into and out of operativeposition.

17. Apparatus for receiving rotating tubes from cross-rolls comprising adelivery table having rollers for guiding the longitudinal movement ofsaid tubes and rollers for supporting said tubes, and means forefl'ecting relative vertical adjustment of the guide rollers and thesupporting rollers to adapt them for cooperation with tubes of variousdiameters.

18. Apparatus for receiving rotating tubes from cross-rolls comprising adelivery table having centrally disposed supporting rollers and guiderollers laterally spaced from the line of supporting rollers forengaging said tubes,- and means for adjusting the vertical positions ofsaid supporting rollers to insure proper engagement of all said rollerswith tubes of different diameters.

19. The combination with a pair of cross-rolls from which tubes emergewith a helical movement, of a delivery table for receiving andsupporting said tubes and comprising rotatable rollers having surfacesfor engaging said tubes, and power-driven means for moving said rollersaxially thereof at approximately the same rate as the longitudinal.progression of the tubes, whereby the points of the surfaces of saidmlhrs move in helical paths.

AUGUST P. DIESCHIR.

CERTIFICATE or CORRECTION.

- Patent No. 1,992,360. .February 26, 1935.

AUGUST' P. DIESCHER.

It is hereby certified that error appears in the printed specificationof the the above numbered patent requiring correction as follows: Page5, first column, line 28, claim 13, after 'means" insert the wordsindependent of said cross-rolls and saidtubes; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 9m day at April, A. n. 1935.

Leslie Frazer (Seal) I Acting bfimmissioner of Patents

